Chuck.



0. EBERT.

CHUCK.

APrLIoA'rIoN FILED om". s, 1912.

Patented July 22, 1913.

j @j if 54 /giifi lUNlTFLD @Fhlt OTTO EBERT, OF CLEVELAND, OHIO.

CHUCK.

Application led October 3, 1912.

To all whom, t may concern:

Be it known that 1, C'r'ro Eisner, citizen ot the United States, residing at Cleveland, in the county of Cuyahoga and State ot Chio, have invented certain new and useful lmprovements in Chucks, of which the following is a specification.

This invention relates to chucks or vises for machine tools, such as planers, millers and other metal working machines, and has for its obj ect to provide improved means tor pulling down the work, so as to clamp the same flatly on the base ot' the chuck.

For the sake of accuracy it is essential that the work be held exactly level or 'flat against the base. l/Vith ordinary chucks etiorts are often made to reach this result by hammering the work down, but when this is done it has been found that the work will rebound to a certain extent, or the jaws will spring the work, with objectionable results. By the present invention l employ movable tace plates on the jaws, which by means oit screws can be forced down to hold the work perfectly against the base.

The invention is illustrated in the accompanying drawings in which- Figure 1 is a vertical longitudinal section of the chuck. Fig. 2 is a horizontal section. Fig. 3 is a section on the line 3-3 of Fig. 1. Fig. t is a back view of one of the jaw plates. Fig. 5 is a section on the line 5 5 ot Fig. 1.

Referring specifically to the drawings, 30 indicates the base or bed plate of the chuck, and this is provided with the fixed jaw 8 and the movable jaw 7 operated by a screw 6 with langes 13 to prevent the travel of the screw. The movable jaw is clamped to adjusted position by bolts 11, the heads of which slide in undercut slots 12 in the bed plate. These parts are not substantially ditt'erent from known chucks. T he flanges 13 bear against a block or lower bearing piece- 15, held by an upper bearing piece 14 and bolts 16, the bearing pieces being mortised into the bed plate.

Each jaw 7 and 8 is provided with a movable jaw plate 9, slidable up and down thereon, operated by a screw 10 tapped into the jaw and having a collar 10a which engages in a groove 2() in the back ot the jaw plate. This screw may be operated by a socket Specification of Letters Patent.

Patented July 22, 1913.

Serial No. 723,746.

wrench, to raise or lower the jaw plates. The jaw plates are confined and guided on the jaws by means of angular guide pieces 17 at opposite sides, said guide pieces being secured to the jaw plates by screws 19 and traveling` in guide grooves 18 in the sides ot the jaw.

In use, the work is placed between the jaws and clamped by means of the screw 6; then the screws 10 are turned so as to torce the jaw plates 9 downwardly until the work held by these plates rests level and solidly on the base. The clamp bolts 11 may be tightened to hold the movable jaw firmly. It will be noticed that in all positions of the jaw plates they remain in contact with and are supported by the jaws, which is highly advantageous with respect to strength and rigidity.

I claim:

1. ln a machine chuck, the combination with a bed plate and jaws, of jaw plates adapted to clamp the work therebetween, and slidable on the jaws toward the bed plate, and pressure means engaging between the jaws and the plates to e'iiiect said sliding movement after the work is clamped, to seat and hold the work with pressure against the bed plate.

2. in a machine chuck, the combination with the bed plate and jaws thereon, of jaw plates adapt-ed to clamp the work therebetween, and slidable on the jaws toward the bed plate, and screws mounted on the jaws and engaging said jaw plates to so slide the same., after the work is so clamped, to seat the work againstl the bed plate.

3. In a machine chuck, the combination with a bed plate and jaws thereon, of jaw plates slidable on the jaws, said plates having grooves in the back thereof, and screws mounted in the jaws and having collars bearing downwardly on the jaw plates in said grooves to move the plates with respect to the jaws and torce the work against the bed plate.

In testimony whereof, l do aliix my signature in presence ot two witnesses.

OTTO FBERT.

idlitnesses J orf-1N A. BoMMrrAnDT, HARRY L. R101-ini.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

